Extending an Alternative to Feynman Diagrams

Scattering amplitudes are the key ingredients for making theoretical predictions about what particle physics experiments will observe. Knowing them allows you to calculate the probability that interacting particles will scatter into a certain collection of particles. A team of theorists from the California Institute of Technology in Pasadena and Charles University in Prague (Cheung et al.) has now outlined how to extend a modern technique for calculating these amplitudes to a class of physical theories known as effective field theories [1]. Such theories are encountered in descriptions of pion interactions and in attempts to extend the standard model, and the work might lead to innovative approaches to solving problems in these areas. But the main interest in this technical advance is that it takes a step toward reformulating quantum field theories in a new way.